Duplicated fie genes in maize:: Expression pattern and imprinting suggest distinct functions
Duplicated fie genes in maize:: Expression pattern and imprinting suggest distinct functions
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DOI：
10.1105/tpc.006759
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发表时间：
2003-02-01
期刊：
影响因子：
11.6
通讯作者：
Ananiev, EV
中科院分区：
文献类型：
--
作者：
Danilevskaya, ON;Hermon, P;Ananiev, EV
克隆并分析了两个与拟南芥FIE（受精-非依赖性胚乳）蛋白（在没有受精的情况下胚乳发育的抑制因子）具有预测翻译相似性的玉米基因。fie 1和fie 2的基因组序列在编码区内显示出显著的同源性，但在内含子内或5'上游没有同源性。fie 1基因仅在授粉后6天左右发育中的籽粒胚乳中表达。FIE 1是一个印记基因，在籽粒发育过程中没有检测到父本来源的FIE 1等位基因的表达。相反，fie 2在授粉前在胚囊中表达。授粉后，其表达持续存在，主要在胚中，胚乳中的表达水平较低。父本fie 2等位基因在籽粒发育早期不表达，但其转录在授粉后5天被激活。fie 2可能是拟南芥FIE基因的功能性直系同源物，而fie 1已经进化出独特的功能。玉米FIE 2和高粱FIE蛋白形成一个单系群，彼此之间的关系比与FIE 1蛋白的关系更近，表明玉米FIE基因起源于两个不同的祖先基因组。
Two maize genes with predicted translational similarity to the Arabidopsis FIE (Fertilization-Independent Endosperm) protein, a repressor of endosperm development in the absence of fertilization, were cloned and analyzed. Genomic sequences of fie1 and fie2 show significant homology within coding regions but none within introns or 5' upstream. The fie1 gene is expressed exclusively in the endosperm of developing kernels starting at similar to6 days after pollination. fie1 is an imprinted gene showing no detectable expression of the paternally derived fie1 allele during kernel development. Conversely, fie2 is expressed in the embryo sac before pollination. After pollination, its expression persists, predominantly in the embryo and at lower levels in the endosperm. The paternal fie2 allele is not expressed early in kernel development, but its transcription is activated at 5 days after pollination. fie2 is likely to be a functional ortholog of the Arabidopsis FIE gene, whereas fie1 has evolved a distinct function. The maize FIE2 and sorghum FIE proteins form a monophyletic group, sharing a closer relationship to each other than to the FIE1 protein, suggesting that maize fie genes originated from two different ancestral genomes.